I'd like to thank Terry Schenold for his thoughtful and thorough review. There are a number of items I feel fortunate to be able to respond to or reflect on here.

First, I am thankful that Schenold points out the difference between a system/unit distinction and the binary opposition. Since this is a point I often find myself clarifying, it's worth saying a bit more about this. Units often assemble themselves into systems: the algorithms in a code library; the metrical feet in a line of poetry; the cogs in a machine. Likewise, these systems often become units themselves in different systems: the code library in a software framework in an operating system; the line in a stanza in a sonnet; the machine in a production line within an economy. The relationships between such structures are not binary nor are they simply hierarchical. They relate in complex ways, and those complexities combine with one another. One confusion that Schenold was kind enough not to point out is that between "system" as an assemblage of units and "system" as a deterministic structure. There is an unfortunate semantic collision here that one must heed. In a context like this I can urge the reader to consider the difference between "system" and "system operation."

Second, I find myself particularly enamored of this characterization: "Bogost ... is after readings of the procedural experiences in their particular configurations." What I like about this is that it aligns a source process (e.g. brewing tea, falling in love, sacking a city, etc.) with its target procedural representation. Something I've found interesting in conversations with colleagues since the book's publication is how seemingly unfashionable such a move seems in contemporary scholarship. At the risk of gross overgeneralization, we have formalist and functional analyses that seek to understand how things are, ethnographic ones that seek to understand how people use them, and media ecological ones that seek to understand the forces they exert on culture. I've found that belief in games (or many other media, for that matter) as representational strikes many as anachronistic. Interestingly, there is also a relatively small amount of scholarly "readings" of videogames, despite the increased popularity and respect the field of game studies has garnered. I'm happy that Schenold points to Alex Galloway's Gaming (a book I enjoyed, but often disagree with) as a counterpoint in this regard.

One way that I'm trying to take charge further is in a new book series called Platform Studies, housed at the MIT Press and co-edited by myself and Nick Montfort (author of Twisty Little Passages). Platform Studies investigates the relationships between the hardware and software design of computing systems and the creative works produced on those systems. It continues the interest I have in the formal and material aspects of computer media, while continuing to insist on the ways those formal aspects inform or influence actual artifacts. The strongest corollary to this approach in Unit Operations can be found in the sections on Pong and Tank, and on game engines. The first book in the Platform Studies series, which Nick and I also co-authored, will be published in early 2009; it's about the Atari VCS (2600).

Third, Schenold's explicit connection between units and memes reminds me of work still to be done, namely distinguishing between the unit operation and other types of literary or artistic gestures. There are similarities between unit operations and certain literary tropes, e.g. the leitmotif. But the distinction between the trope and the unit is one of function more than style. It is not merely the image or pattern of Benjamin's "figure that fascinates" that recurs in Baudelaire, Bukowski, Jeunet, and Wright, but its very logic.

Fourth, I want to respond to Schenold's very fair complaint about that the book may leave the reader with approach but not method. I suppose if I were trying to defend myself, I'd say that I never promised the latter. A more clever response might argue that any method risks ossifying into a system operation, a move I'd clearly want to avoid. But the concept of the bricoleur, and that of the reconfiguration of the university (both discussed in the review) also offer some perspective. The sort of good games criticism we all hope for depends not only on a mastery of different forms of human expression but also on the different subjects and purposes of that effort.

Fifth, on the subject just mentioned, I'd like to offer a few comments on the book's final chapter on re-imagining the university. Since the book's publication, I've heard at least one concrete, complementary suggestion, albeit just as theoretical: Katherine Hayles concept of academic "clusters" in her Professionalization in a Digital Age (PDF) talk, presented at the 2007 MLA. I suppose it should come as no surprise that Hayles was co-chair of my dissertation committee, and that our ideas have, I think, influenced one another. I likewise tried to consider this topic again in a somewhat unusual keynote at the 2008 Game Developers Conference Education Summit, entitled Not Interdisciplinarity, but Love. The core of my argument was that healthy interconnectedness is messy, not antiseptic.

Finally, I want to agree with Schenold's suggestion that Unit Operations may be rough going for the early undergraduate student or the casual reader. That said, I'll take the opportunity to make two contrapuntal observations. One, I do hope and believe that this book takes a much more lucid approach to theory than the post-'68 critical theory tradition in which I was intellectually reared, and which seems to have fallen thoroughly out of fashion. Two, I believe there is still a place for "hard" theory, ideas that are rich enough to require deep thought to access, master, and critique -- even when the subject of that theory is a medium as accessible as the videogame.